So I decided to add another chip (pic18f46j50) to my IOIO to generate a nice PPM signal.

After that I used nearly the same board to catch Accelerometer, gyroscope, barometric pressure and temperature (ms5607) and GPS and to send it in the Frsky receiver, and plugged the frsky transmitter to the IOIO board.

So I'm able to retrieve the data sent according to the frsky protocol and data from my custom hub and display it on a custom android app :

Now I'm planing on remaking a complete pcb including the IOIO chip and my ppm chip, potentiometer, switchs, ...